Tappet end rocker arms 1956 G80S

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56G80S
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Joined: Wed Oct 12, 2005 10:45 pm
Location: N YORKS UK

Tappet end rocker arms 1956 G80S

Post by 56G80S »

Hi All

I've been cleaning up in preparation for reassembling the engine. Everything was completely filthy.

While cleaning the rocker box I noticed that the there was a little "pimple" corresponding with the small hole in the cup of the pushrods. For some reason I had never noticed these before. I was thinking of popping off the arms and stoning the pimples off.

Any thoughts on this? ?Thankfully the bushes I fitted in the rocker box many years ago show no play so that's a help!

I then remembered that a fellow member had very helpfully sent me a LIGHTWEIGHT rocker arm FOC so I could modify and get a little more zip. When I looked at it, the rocker bearing surface into the push rod looks like it had a bad attack of acne in contrast with the smooth shiny surface (except pimple) of the ones in situ. I wonder if this can simply be re-surfaced or should I buy a new one - if available.

Update There's a 042043 rocker arm (supposedly) om boaspares.com for 12.5 euros. But the measurement shown, between centre of shaft hole and point of the surface bearing on the pushrod is shown as 25.2 mm or just short of an inch. This is different to the one I have in hand, mentioned above. The one I have in hand is, as it should be, about 1/8" shorter than the ones I have fitted and the equivalent measurement to the boaspares one is 3cms (or 1&3/16").

Any thoughts on this?

As an aside, I can't find the SH cam I used to have in anywhere, it's been running on standard cams for many years.

Johnny B
markwhitelock
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Joined: Sat Sep 07, 2019 5:51 pm
Location: Hampshire UK

Re: Tappet end rocker arms 1956 G80S

Post by markwhitelock »

Hi Jonny

My rocker had developed the same tiny nipple, I think it may be where the hardened surface of the tip had been worn away. I replaced with new ones from the club shop
56G80S
Member
Posts: 3354
Joined: Wed Oct 12, 2005 10:45 pm
Location: N YORKS UK

Re: Tappet end rocker arms 1956 G80S

Post by 56G80S »

Hi Mark

Cheers! I didn't know that they were hardened. They've been on since the mid 1970's and I've not had a problem with running out of adjustment, which I would've thought would happen.

Perhaps I need to take a closer look at the pushrods too.

Thanks

Johnny B
Mick D
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Location: Aberdeenshire

Re: Tappet end rocker arms 1956 G80S

Post by Mick D »

Hi

I wouldn't lose any sleep over this as long as the clearance doesn't keep coming out of adjustment. Refit everything as was, you did note which rod was which didn't you?

Regards Mick
56G80S
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Posts: 3354
Joined: Wed Oct 12, 2005 10:45 pm
Location: N YORKS UK

Re: Tappet end rocker arms 1956 G80S

Post by 56G80S »

Hi Mick, sensible as ever. I only thought to stone off the pips in case they come off and move round where they shouldn't.

What else is masking tape for? I even push bolts through a cardboard "template" and put them back where they came from. Nuts and bolts remain matched. OCD or what?

I'm not rushing things any more than necessary but am still seeking an answer to the question about the dimensions of the 042043 rocker arm.

Thanks

Johnny B
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